The effect of high dose intravenous labetalol on plasma glucose during surgery.

As high dose intravenous labetalol was always used in performing deliberate hypotensive anesthesia and it was reported that small dose of intravenous labetalol would decrease the hyperglycemic response under surgical stress, high dose intravenous labetalol may theoretically causes more pronounced reduction in plasma glucose. 14 female cervical cancer patients (ASA physical status I-II) undergoing radical total hysterectomy were selected and randomly assigned into two groups (group A and group B). The anesthesia was induced with 2.5% sodium thiopental 4 mg/kg, atropine 0.3 mg, succinylcholine 1.5 mg/kg and fentanyl 3 micrograms/kg intravenously. The anesthesia was maintained with isoflurane, nitrous oxide, oxygen and vecuronium under artificial controlled ventilation. Radial artery was cannulated for continuous blood pressure monitoring and blood sampling. The first sample was taken after intubation and before skin incision and the second sample was taken 5 minutes after skin incision in group A and after giving total dose of labetalol in group B, other blood samples were taken every 30 minutes thereafter. No labetalol was given in group A patients. In group B, labetalol (1.0-1.5 mg/Kg) was administrated intravenously in repeated bolus (10 mg/bolus) to achieve a mean blood pressure around 60 torr after skin incision. All the fluid administered intraoperatively was free of glucose. Any patients with blood loss greater than 1000 ml or having blood transfusion before the 5th samples (S5) were excluded because stored blood was rich of glucose. The result revealed that plasma glucose rose significantly in both groups but the rise occurred later in group B.(ABSTRACT TRUNCATED AT 250 WORDS)